2M1207

Starbox begin
name = 2M1207Starbox image


caption = European Southern Observatory infrared image of 2M1207 (bluish) and companion planet 2M1207b (reddish), taken in 2004.Starbox observe
epoch = J2000.0 (ICRS)
constell = Centaurus
ra = RA|12|07|33.47
dec = DEC|−39|32|54.0
appmag_v = 20.15An accurate distance to 2M1207Ab, C. Ducourant, R. Teixeira, G. Chauvin, G. Daigne, J.-F. Le Campion, Inseok Song, and B. Zuckerman, "Astronomy and Astrophysics" 477, #1 (January 2008), pp. L1–L4. bibcode|2008A&A...477L...1D doi|10.1051/0004-6361:20078886.] Starbox character
v-r = 2.1
r-i = 2.1
class = M8Starbox astrometry
parallax = 19.1
p_error = 0.4
parallax_footnote =
dist_ly = 172 ± 3
dist_pc = 52.75 ± 1.0Starbox detail
mass = ~0.025
temperature = 2550 ± 150The Planetary Mass Companion 2MASS 1207-3932B: Temperature, Mass, and Evidence for an Edge-on Disk, Subhanjoy Mohanty, Ray Jayawardhana, Nuria Huelamo, and Eric Mamajek, "Astrophysical Journal" 657, #2 (March 2007), pp. 1064–1091. bibcode|2007ApJ...657.1064M doi|10.1086/510877.]
age = 5·10⁶ to 10·10⁶
radius = ~0.25
luminosity = ~0.002Starbox catalog
names = 2MASSW J1207334−393254SIMBAD link|NAME+2M1207A|NAME 2M1207A, entry, SIMBAD. Accessed on line June 15, 2008.] Starbox reference
Simbad = NAME+2M1207A

2M1207, 2M1207A or 2MASSW J1207334−393254 is a brown dwarf located in the constellation Centaurus; a companion object, 2M1207b, may be the first extrasolar planetary mass companion to be directly imaged, and is the first discovered orbiting a brown dwarf.

2M1207 was discovered during the course of the 2MASS infrared sky survey: hence the "2M" in its name, followed by its celestial coordinates. With a fairly early (for a brown dwarf) spectral type of M8, it is very young, and probably a member of the TW Hydrae association. Its estimated mass is around 25 Jupiter masses. The companion, 2M1207b, is estimated to have a mass of 3–10 Jupiter masses. [http://exoplanet.eu/star.php?st=2M1207 Star: 2M1207] , "Extrasolar Planets Encyclopaedia". Accessed on line June 15, 2008.] Still glowing red hot, it will shrink as it cools over the next few billion years.

An initial photometric estimate for the distance to 2M1207 was 70 parsecs. In December 2005, American astronomer Eric Mamajek reported a more accurate distance (53 ± 6 parsecs) to 2M1207 using the moving cluster method. [cite journal | url=http://adsabs.harvard.edu/abs/2005ApJ...634.1385M | author=Mamajek| title= A Moving Cluster Distance to the Exoplanet 2M1207b in the TW Hydrae Association | journal= The Astrophysical Journal| volume=634 | year=2005 | pages=1385–1394| doi= 10.1086/468181 ] The new distance gives a fainter luminosity for 2M1207. Recent trigonometric parallax results have confirmed this moving cluster distance, leading to a distance estimate of 53 ± 1 parsec or 172 ± 3 light years. [http://www.cfa.harvard.edu/~emamajek/memo_2m1207.html "The Distance to the 2M1207 System"] , Eric Mamajek, November 8, 2007. Accessed on line June 15, 2008.]

Like classical T Tauri stars, many brown dwarfs are surrounded by disks of gas and dust which accrete onto the brown dwarf. [ [http://origins.jpl.nasa.gov/library/extrasolar/121302-a.html More Sun-like stars may have planetary systems than currently thought] , library, Origins program, NASA. Accessed on line June 16, 2008.] First Ultraviolet Spectrum of a Brown Dwarf: Evidence for H₂ Fluorescence and Accretion, John E. Gizis, Harry L. Shipman, and James A. Harvin, "Astrophysical Journal" 630, #1 (September 2005), pp. L89–L91. bibcode|2005ApJ...630L..89G doi|10.1086/462414.] 2M1207 was first suspected to have such a disk because of its broad H_α line. This was later confirmed by ultraviolet spectroscopy. The existence of a dust disk has also been confirmed by infrared observations. [Spitzer Observations of Two TW Hydrae Association Brown Dwarfs, Basmah Riaz, John E. Gizis, and Abraham Hmiel, "Astrophysical Journal" 639, #2 (March 2006), pp. L79–L82. bibcode|2006ApJ...639L..79R doi|10.1086/502647.] In general, accretion from disks is known to produce fast-moving jets, perpendicular to the disk, of ejected material. [Accretion-ejection models of astrophysical jets, R. E. Pudritz, in "Accretion Disks, Jets and High-energy Phenomena in Astrophysics", Vassily Beskin, Gilles Henri, Francois Menard, Guy Pelletier, and Jean Dalibard, eds., NATO Advanced Study Institute, Les Houches, session LXXVIII, EDP Sciences/Springer, 2003. ISBN 3540201718.] This has also been observed for 2M1207; an April 2007 paper in the "Astrophysical Journal" reports that this brown dwarf is spouting jets of material from its poles. [cite journal | doi= 10.1086/516734 | author=Whelan "et al."| title= Discovery of a Bipolar Outflow from 2MASSW J1207334-393254, a 24 MJup Brown Dwarf| journal= The Astrophysical Journal| volume=659 | date=April 10, 2007 | pages=L45 – L48 | bibcode = 2007ApJ...659L..45W ] The jets, which extend around 10⁹ kilometers into space, were discovered using the Very Large Telescope (VLT) at the European Southern Observatory. Material in the jets streams into space at a few kilometers per second. [http://www.space.com/scienceastronomy/070528_mm_bdwarf_jets.html Small Stars Create Big Fuss] , Ker Than, May 28, 2007, space.com. Accessed on line June 15, 2008.]

OrbitboxOnePlanet
exoplanet = b
mass = 3–10
separation = 40.6 ± 1.3 [From estimated distance of 52.75 ± 1.0 parsec and observed angular separation of 769 ± 10 milliarseconds (angular separation from Mohanty 2007, above.) ]

References

External links

* [http://space.com/scienceastronomy/aas_exoplanet_050110.html Space.com - Astronomers Confident: Planet Beyond Solar System Has Been Photographed]
* [http://www.space.com/scienceastronomy/planet_photo_040910.html Space.com article on the discovery]
* [http://exoplanet.eu/star.php?st=2M1207 Extrasolar Planets Encyclopedia page on 2M1207]
* [http://www.sc.eso.org/~gchauvin/Gg222.pdf "A Giant Planet Candidate Near a Young Brown Dwarf" (PDF)] from the European Southern Observatory.
* [http://arxiv.org/abs/astro-ph/0507416 "A Moving Cluster Distance to the Exoplanet 2M1207b in the TW Hydrae Association"]
* [http://www.cfa.harvard.edu/~emamajek/memo_2m1207.html "The Distance to the 2M1207 System"]